Reckless. At the start of its turn, the gibberling can gain advantage on all melee weapon attack rolls during that turn, but attack rolls against it have advantage until the start of its next turn.
Burrow. A gibberling gains advantage on stealth checks if it uses an action to burrow into dirt.
Light Sensitivity. While in bright light, gibberlings have disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.
Dagger. Melee Weapon Attack: +4 to hit, reach 5 ft., one
target. Hit: 4 (1d4 + 2) piercing damage.
Swarm. Melee Weapon Attack: +4 to hit, reach 5 ft., one
target. The target is grappled (escape DC 10). All
gibberlings within 5 ft. of the target can use a
reaction to make a dagger attack with advantage
on the attack roll.
Source: MaBJoV, page 141